JP3707180B2 - Method for producing reactive resin water dispersion - Google Patents

Description

【００３４】
【表２】

【００３５】
○評価
各例で得られた反応性樹脂水分散体を、以下の方法で評価した。それらの結果を表３に示す。
【００３６】
・作業性評価
○：作業上問題なし。
△：多少粘度が高いが、取り扱うことができる。。
×：粘度が高いために取り扱いづらい。
【００３７】
・加熱安定性試験
各例で得られた反応性樹脂水分散体を、４０℃にて２００時間放置した後、目視による外観で評価した。
◎：全く変化なし。
○：ほとんど粘度上昇なし。
△：粘度上昇あり。
×：凝集物、沈殿物が発生。
【００３８】
・硬化性試験
得られた反応性樹脂水分散体の固形分１００部に対して、イルガキュア２９５９〔チバガイギー（株）社製〕２部を配合して組成物を製造した。この組成物を、ボンデライト鋼板ＰＢ−１４４〔日本テストパネル（株）製〕に膜厚２０ミクロンで塗布したのち、８０℃のオーブンで５分間乾燥させたのち、これを８０Ｗ／ｃｍ、集光型高圧水銀灯１灯を用いて、ランプ高１０ｃｍで紫外線を照射し、硬化に要した照射量を測定した。
尚、表における◎、○、△及び×は以下の意味を示す。
◎：５００mJ/cm2未満で完全に硬化
○：５００以上１０００mJ/cm2未満で硬化
△：１０００mJ/cm2以上で硬化
×：１０００mJ/cm2以上でも硬化しない
【００３９】
・硬度
硬化性試験により得られた硬化膜について、ＪＩＳの「手かき法Ｋ５４００」に従い評価した。
【００４０】
・着色評価
硬化性試験により得られた硬化膜の着色を、目視により評価した。
尚、表における○、△及び×は以下の意味を示す。
○：着色は全くみられない
△：わずかに着色がみられる
×：着色がみられる
【００４１】
【表３】

【００４２】
【発明の効果】
本発明の製造方法は、カルボキシル基含有重合体に対するエポキシ基含有（メタ）アクリレートの付加反応性を工業的に有利に行うものであり、又得られる反応性樹脂水分散体は、粘度が低く作業性に優れるもので、着色がなく、保存安定性に優れ、又は該樹脂からなる組成物は、硬化性、加熱安定性及び透明性に優れているため、塗料、印刷インキ、接着剤、充填剤、成形材料及びレジスト等の種々の用途に使用でき、その工業的価値はきわめて大きい。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a reactive resin water dispersion curable by irradiation with an active energy ray such as an electron beam or ultraviolet rays, or at room temperature or by heating, and the reactive resin water dispersion produced by the present invention. The body is useful in various industrial fields as paints, printing inks, adhesives, fillers, molding materials and resists.
In the present specification, acrylate and / or methacrylate is represented by (meth) acrylate, acryloyl group and / or methacryloyl group is represented by (meth) acryloyl group, and acrylic acid and / or methacrylic acid is represented by (meth) acrylic acid. .
The unit of the acid value is mg KOH / g, and is expressed in terms of solid content.
[0002]
[Prior art]
In recent years, organic pollution, cleaning agents, and the like used in various industries have been released into the atmosphere, and air pollution on a global scale has progressed. For this reason, in the resin composition used for uses, such as various coating materials, ink, and an adhesive agent, the trial of making solvent-free by water-izing is made | formed.
As one of the methods for making the reactive resin aqueous, a compound having an epoxy group and an unsaturated group is added to a polymer having a carboxyl group, and an unsaturated group which is a reactive group is introduced into the polymer. A reactive resin having a carboxyl group and an unsaturated group is produced, and the resin is neutralized with an alkali. In some cases, the resin is suspended or emulsified in an aqueous solution containing water or an organic solvent such as alcohol using an emulsifier. There is a method (hereinafter referred to as method A, JP-A-51-17922, 51-23531).
In addition, as another method, there is a method in which a polymer having a carboxyl group is produced in water in the presence of a surfactant, and a compound having an epoxy group and an unsaturated group is added to the obtained polymer. Hereinafter referred to as Method B, JP-A-6-221950).
[0003]
[Problems to be solved by the invention]
In the case of the above method A, the reaction of adding a compound having an epoxy group and an unsaturated group to a polymer having a carboxyl group is carried out using a catalyst such as an organic amine in a solvent such as a hydrophilic alcohol or ketone. However, the reaction was not sufficiently reactive, and the reaction took a long time. In order to increase the reactivity, there is a method of increasing the amount of a catalyst such as an organic amine. In this case, since the amount of the catalyst increases, the catalyst forms a large amount of salt with a polymer having a carboxyl group. Therefore, the resulting adduct is difficult to dissolve in a solvent.
In addition, when the resulting reactive resin is made aqueous, it is not only necessary to remove the solvent contained therein by evaporation or the like, but it is difficult to completely remove the solvent from the reactive resin. Therefore, if the product has an odor, or if the solvent is to be distilled off as much as possible, it will take a long time. As a result, the reactive resin has a long anaerobic atmosphere that promotes its curing reaction. Due to exposure to time, the storage stability of the final product may be deteriorated or colored.
In the case of Method B, the resulting reactive resin aqueous dispersion contains a surfactant in the liquid, and thus the cured film of the reactive resin is inferior in water resistance.
The inventors of the present invention have an industrially advantageous method for producing a reactive resin aqueous dispersion having excellent storage stability of a product, no coloring, excellent curability and workability, and a cured film having excellent water resistance. We have conducted an intensive study.
[0004]
[Means for solving problems]
As a result of intensive studies to solve the above problems, the present inventors have found that it is effective to produce a reactive resin by a specific method using a polymer having a specific carboxyl group, and the present invention. Was completed.
Hereinafter, the present invention will be described in detail.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
○ Polymer having (meth) acryloyl group and carboxyl group
In the production method of the present invention, one or more of (meth) acrylates having one or more carboxyl groups (hereinafter referred to as carboxyl group-containing (meth) acrylates), or the ( It is obtained by polymerizing (meth) acrylate and one or more other monomers having one ethylenically unsaturated group (hereinafter referred to as ethylenically unsaturated monomer) under specific conditions (meta ) A polymer having an acryloyl group and a carboxyl group (hereinafter simply referred to as a carboxyl group-containing polymer) is used.
[0006]
Various carboxyl group-containing (meth) acrylates can be used, for example, Michael addition reaction products of unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, cinnamic acid or (meth) acrylic acid. Dimer or higher oligomers, ω-carboxypolycaprolactone mono (meth) acrylate, phthalate monohydroxyethyl (meth) acrylate, succinate monohydroxyethyl (meth) acrylate, and the like.
[0007]
The carboxyl group-containing polymer may be a homopolymer or copolymer of a carboxyl group-containing (meth) acrylate, or a copolymer of this carboxyl group-containing (meth) acrylate and an ethylenically unsaturated monomer. There may be.
Various ethylenically unsaturated monomers other than the carboxyl group-containing (meth) acrylate can be used, such as styrene, α-methylstyrene, (meth) acrylonitrile, vinyl acetate and (meth). An acrylate etc. are mentioned. Specific examples of (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and alkyl (meth) acrylate such as 2-ethylhexyl (meth) acrylate, cyclohexyl Alkoxy (such as alicyclic alkyl (meth) acrylate such as (meth) acrylate), substituted aryl (meth) acrylate such as benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate ( Examples include (meth) acrylates, isobornyl (meth) acrylates, and hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate.
[0008]
The copolymerization ratio of the carboxyl group-containing (meth) acrylate and the ethylenically unsaturated monomer is arbitrary on condition that the acid value of the resulting carboxyl group-containing polymer is a value satisfying the acid value shown below. It is.
[0009]
The carboxyl group-containing polymer used in the present invention needs to have an acid value of 50 to 500, preferably 100 to 300. When the acid value is less than 50, the carboxyl group-containing polymer is dissolved in an alkaline aqueous medium in the addition reaction with (meth) acrylate having one epoxy group (hereinafter referred to as epoxy group-containing (meth) acrylate) described later. There is a problem in that addition reactivity is lowered, or dissolution or dispersion takes time because of insufficient solubility or dispersibility. As a means for improving the solubility or dispersibility of the carboxyl group-containing polymer, there is a method of lowering the solid content concentration of the carboxyl group-containing polymer in an aqueous solution or dispersion. At this time, the reactive resin aqueous dispersion obtained However, since it contains a large amount of an aqueous medium, it becomes inferior in drying property. On the other hand, when the acid value is higher than 500, the viscosity of the resulting reactive resin water dispersion becomes high.
[0010]
The number average molecular weight of the carboxyl group-containing polymer needs to be 1,000 to 15,000, preferably 2,000 to 10,000. If this value is less than 1,000, the resulting reactive resin has poor adhesion and adhesion to the substrate, and the strength of the coating film is not sufficient. On the other hand, when this value exceeds 15,000, the solubility or dispersibility in an alkaline aqueous medium becomes poor, as in the case where the acid value is less than 50. If the solid content concentration of the carboxyl group-containing polymer is lowered, the solubility or dispersibility can be improved, but the resulting reactive resin water dispersion will be inferior in drying property. Furthermore, such a carboxyl group-containing polymer having a high number average molecular weight is inferior in reactivity with the epoxy group-containing (meth) acrylate, so that the introduction ratio of (meth) acryloyl groups into the reactive resin becomes insufficient. The resulting reactive resin is inferior in curability, and the hardness and strength of the coating film are reduced.
In the present invention, it is preferable to use a polydispersity (Mw / Mn) which is a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the copolymer is 3 or less. More preferably, it is 2.5 or less. A carboxyl group-containing polymer having a polydispersity in this range is excellent in solubility in an alkaline aqueous medium and is particularly suitable for producing a reactive resin aqueous dispersion having a low viscosity.
In the present invention, the number average molecular weight and the weight average molecular weight are values obtained by converting the molecular weight measured by gel permeation chromatography (hereinafter abbreviated as GPC) based on the molecular weight of polystyrene using tetrahydrofuran as a solvent. is there.
[0011]
In the present invention, as a carboxyl group-containing polymer, a carboxyl group-containing (meth) acrylate or a polymer obtained by polymerizing the (meth) acrylate and an ethylenically unsaturated monomer at a high temperature of 150 to 310 ° C. is used. Preferably, high temperature continuous polymerization is used.
According to this high-temperature continuous polymerization method, a polymer having a lower polydispersity than that obtained by conventional solution polymerization can be obtained, and it is not necessary to use a thermal polymerization initiator, or a thermal polymerization initiator is used. Even in such a case, since a carboxyl group-containing polymer having a target molecular weight can be obtained with a small amount of use, a highly pure carboxyl group-containing polymer containing almost no impurities that generate radical species by heat or light can be obtained. The addition reaction of the carboxyl group-containing polymer and the epoxy group-containing (meth) acrylate described in the above can be performed stably, and the finally obtained reactive resin aqueous dispersion has excellent storage stability, and the coating film Excellent weather resistance.
[0012]
Several proposals have already been made on the high-temperature continuous polymerization method, and for example, a known method disclosed in JP-A-57-502171, 59-6207 and 60-21.507 may be used.
For example, after filling a pressurizable reactor with a solvent and setting the pressure to a predetermined temperature under pressure, the carboxyl group-containing (meth) acrylate, the (meth) acrylate and the ethylenically unsaturated monomer, or these are necessary. Accordingly, there may be mentioned a method in which a monomer mixture comprising a polymerization solvent is supplied to the reactor at a constant supply rate, and an amount of the reaction liquid corresponding to the supply amount of the monomer mixture is withdrawn.
When using a polymerization solvent, the solvent charged into the reactor at the start of the reaction and the polymerization solvent mixed in the monomer mixture may be the same or different. Solvents or polymerization solvents include aliphatic hydrocarbons, aromatic hydrocarbons such as toluene, xylene, cumene and ethylbenzene, cellosolves such as butyl cellosolve, glycol ethers such as carbitol, glymes such as ethylene glycol dimethyl ether, and diglymes such as diethylene glycol dimethyl ether. Such as ether, ethyl acetate, butyl acetate, cellosolve acetate, methyl propylene glycol acetate, acetate such as carbitol acetate and ethyl carbitol acetate, ketones such as acetone and methyl ethyl ketone, hexanol, decanol, ethylene glycol, propylene glycol and butylene glycol Aliphatic alcohols such as, aromatic alcohols such as benzyl alcohol and toluene alcohol, and Ethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, can be used polyalkylene glycols such as tetramethylene glycol and polytetramethylene glycol. The use ratio of the polymerization solvent is preferably 200 parts by weight or less with respect to 100 parts by weight of the monomer mixture.
In addition, the monomer mixture can be mixed with a thermal polymerization initiator, if necessary, and the thermal polymerization initiator that can be used in this case is not particularly limited, but an azonitrile-based initiator and peroxide. And the like. Azonitrile-based initiators include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) and 2,2'-azobis (2,4-dimethylvaleronitrile) Examples of the peroxide-based disclosure agent include hydrogen peroxide, di-t-butyl peroxide and benzoyl peroxide. When the thermal polymerization initiator is blended in the monomer mixture, the amount is preferably 0.001 to 5 parts by weight with respect to 100 parts by weight of the monomer mixture.
The reaction temperature must be 150-310 ° C. When the temperature is less than 150 ° C, there is a problem that the molecular weight of the resulting polymer becomes too large or the reaction rate becomes slow. On the other hand, when the temperature exceeds 310 ° C, a decomposition reaction occurs and a reaction occurs. The liquid is colored, the addition reaction described later becomes unstable, or the resulting reactive resin becomes unstable. The pressure does not affect the reaction, depends on the reaction temperature, the monomer mixture used and the boiling point of the solvent, and may be any pressure that can maintain the reaction temperature. The residence time of the monomer mixture is preferably 2 to 60 minutes. If the residence time is less than 2 minutes, the amount of unreacted monomers increases, and the yield of the carboxyl group-containing polymer may decrease. On the other hand, if the residence time exceeds 60 minutes, Incurs a decline.
[0013]
-Production method of reactive resin water dispersion
In the production method of the present invention, the polymer is dissolved or dispersed in an alkaline aqueous medium, and the epoxy group of the epoxy group-containing (meth) acrylate is added to the carboxyl group of the polymer. In the present invention, the addition reaction is carried out in an alkaline aqueous medium, not in an organic solvent. In water, the alkali component that acts as a catalyst for the addition reaction can be present at a high concentration, so that the addition reaction in an aqueous medium is much faster than the reaction in an organic solvent, and the reactivity obtained by the addition reaction. Since the resin is obtained as a dispersion, it has a low viscosity and excellent coatability. Furthermore, in the present invention, the reactive resin is compared with a method of adding an epoxy group-containing (meth) acrylate in an organic solvent, then removing the solvent and then dispersing in water to produce a reactive resin aqueous dispersion. Is obtained as a water dispersion in one stage, and the resulting reactive resin water dispersion is free from problems such as odor and coloring.
[0014]
As the production method, various methods can be adopted. For example, a carboxyl group-containing polymer is dissolved or dispersed in an alkaline aqueous medium, and an epoxy group-containing (meth) acrylate is added to the aqueous solution or dispersion, A method of heating and stirring can be mentioned.
In this case, the reaction temperature is preferably 60 ° C to 100 ° C. When the carboxyl group-containing polymer is dissolved in an alkaline aqueous medium by the addition reaction, it becomes a reactive resin and disperses in water, and when dispersed in an alkaline aqueous medium, It becomes a functional resin and maintains a dispersed state in water as it is.
[0015]
In the production method of the present invention, as an epoxy group-containing (meth) acrylate that undergoes addition reaction with a carboxyl group of a carboxyl group-containing polymer, glycidyl (meth) acrylate is obtained, and the reactive resin obtained is present in the molecule (meta ) This is preferable because the ratio of the acryloyl group is high and the reactivity is excellent.
[0016]
The reaction ratio of the epoxy group-containing (meth) acrylate to the carboxyl group in the carboxyl group-containing polymer is preferably such that the acid value of the reactive resin after the addition reaction is 20 to 200.
When the acid value of the reactive resin after the addition reaction is less than 20, the dispersibility of the resulting reactive resin aqueous dispersion is not sufficient, and the resin component may aggregate or precipitate. On the other hand, when the acid value exceeds 200, the produced reactive resin dissolves without being dispersed in water, so that the viscosity becomes high and difficult to handle. When the viscosity of the aqueous dispersion becomes high, the viscosity can be lowered by reducing the solid content of the reactive resin, but the aqueous dispersion is not sufficiently dry.
[0017]
In the alkaline aqueous medium used as the reaction medium, various types of alkalis can be used. Examples include inorganic bases such as ammonia, organic amines, and sodium hydroxide. And since water resistance of the coating film obtained can be maintained, ammonia and a low molecular weight organic amine are preferable.
As the low molecular weight organic amine, trialkylamines such as trimethylamine, triethylamine and tributylamine, and hydroxyalkylamines such as N, N-dimethylethanolamine, N-methyldiethanolamine and triethanolamine can be used.
[0018]
As a density | concentration of the alkali component in an alkaline aqueous medium, the ratio from which an alkali component will be 30-70 mol% with respect to the whole quantity of the carboxyl group in a carboxyl group-containing polymer is preferable. When this ratio is less than 30 mol%, the carboxyl group-containing polymer may be difficult to dissolve or disperse in the aqueous medium, and when it exceeds 70 mol%, the resulting reactive resin water dispersion may be dispersed. The odor of ammonia or amine used as an alkali component may remain.
The amount of the alkaline aqueous medium used in the addition reaction is preferably such that the resulting reactive resin aqueous dispersion has a solid content concentration of 10 to 60% by weight.
[0019]
The alkali component in the alkaline aqueous medium acts as a catalyst and the addition reaction proceeds, but a catalyst can be further added as necessary. Examples of the catalyst include high molecular weight tertiary amines such as N, N-dimethylbenzylamine and N, N-dimethylaniline; quaternary ammonium salts such as tetradiethylammonium chloride, tetrabutylammonium bromide and benzyltrimethylammonium chloride. A hydrochloride of secondary amines such as diethylammonium chloride; and phosphorus compounds such as triphenylphosphine.
The preferable addition amount of these catalysts is 0.1 to 10% by weight, more preferably 0.1 to 5% by weight, based on the solid content in the reaction solution.
[0020]
In the addition reaction, it is preferable to add a polymerization inhibitor such as hydroquinone and hydroquinone monomethyl ether or blow molecular oxygen in order to carry out the reaction stably. When using a polymerization inhibitor, 10 wtppm to 2 wt% is preferable with respect to the reaction solution.
[0021]
○ How to use reactive resin water dispersion
The reactive resin aqueous dispersion obtained by the production method of the present invention can be cured by irradiation with an active energy ray such as an electron beam or ultraviolet rays, or at room temperature or by heating, and the various components described below can be used as they are. It can mix | blend and can be used for various uses, such as a coating material, printing ink, an adhesive agent, a filler, a molding material, and a resist.
[0022]
If necessary, an active energy ray-curable monomer that is a reactive diluent can be blended in the reactive resin water dispersion. Active energy ray-curable monomers include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; mono- or di (meth) acrylate of ethylene glycol, methoxyethylene Mono (di) (meth) acrylates of glycols, such as mono (meth) acrylates of glycol, mono or di (meth) acrylates of tetraethylene glycol and mono or di (meth) acrylates of tripropylene glycol; and trimethylolpropane tri (meta ) Polyols such as acrylates, pentaerythritol tri (meth) acrylates or pentaerythritol tetra (meth) acrylates and dipentaerythritol hexaacrylates or alkylene oxides thereof De adduct (meth) acrylate.
The active energy ray-curable monomer is preferably blended at a ratio of 1 to 150 parts by weight per 100 parts by weight of the solid content of the reactive resin water dispersion.
[0023]
In addition, the reactive resin water dispersion may include a filler such as barium sulfate, silicon oxide, talc, clay and calcium carbonate as necessary, and a coloring pigment such as phthalocyanine blue, phthalocyanine green, titanium oxide and carbon black, Various additives such as an adhesion-imparting agent and a leveling agent, and polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, phenothiazine and N-nitrosophenylhydroxylamine aluminum salt can also be blended.
The blending ratio when blending these is preferably 100 parts by weight or less with respect to 100 parts by weight of the solid content of the reactive resin aqueous dispersion. The blending ratio when blending the polymerization inhibitor is preferably 0.00001 to 2% by weight based on the solid content of the reactive resin aqueous dispersion.
[0024]
The active energy ray irradiation method and the heating method in the case of curing the reactive resin may employ a general method known as a radical polymerizable compound curing method.
[0025]
In the case of curing at room temperature or by heating, a polymerization initiator such as an azonitrile-based initiator and a peroxide-based initiator is added to the reactive resin water dispersion. Specific examples of the azonitrile-based initiator and the peroxide-based initiator can be the same as those used in the high-temperature continuous polymerization described above. A desirable ratio of the polymerization initiator is 0.001 to 5 parts by weight with respect to 100 parts by weight with respect to the solid content of the reactive resin aqueous dispersion.
[0026]
Moreover, when hardening by ultraviolet irradiation as an active energy ray, a photoinitiator is mix | blended with the reactive resin water dispersion. When curing with an electron beam, it is not necessary to add a photopolymerization initiator.
Preferable examples of the photopolymerization initiator include water-soluble or hydrophilic photopolymerization initiators Darocur 2959, 1173, 1116, Irgacure 184 [manufactured by Ciba Geigy Co., Ltd.], Cancure ABQ, BTC, QTX [ Manufactured by Shell Chemical Co., Ltd.], and benzoin, benzoin methyl ether, benzophenone, benzyldimethyl ketal, 2,4-dimethylthioxanthone, etc., which are usually used in a solvent system or a solventless system, can also be used. Moreover, two or more kinds of photopolymerization initiators can be used in combination as required.
The photopolymerization initiator is preferably blended in an amount of 0.1 to 10% by weight based on the solid content of the reactive resin aqueous dispersion.
As a method for adding a photopolymerization initiator, when using a photopolymerization initiator having low solubility in water, the monomer is first dissolved in an active energy ray-curable monomer that is a reactive diluent, and then the monomer. It is preferable to add together. When a water-soluble or hydrophilic photopolymerization initiator is used, it can be added by heating and mixing as it is.
[0027]
When the reactive resin obtained in the present invention is cured by irradiation with active energy rays, the reactive resin aqueous dispersion is usually applied to the substrate, and then water as a dispersion medium is added as ammonia or ammonia or low as an alkaline component. When a molecular weight organic amine is used, it is preferable to evaporate and scatter water and ammonia or a low molecular weight organic amine by heating.
If moisture remains in the cured coating film, the film strength may be insufficient or the transparency of the film may be impaired.
[0028]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. In the following, parts and% are based on weight.
○ Example 1
● Manufacture of carboxyl group-containing polymers
A 300 ml capacity pressurized stirred tank reactor equipped with an electric heater is filled with diethylene glycol monoethyl ether, the temperature is set to 250 ° C., and the pressure is adjusted to 25 to 27 kg / cm using a pressure regulator. ² Kept.
Next, while maintaining the reactor pressure constant, 30 parts of acrylic acid as a carboxyl group-containing (meth) acrylate, 70 parts of styrene as an ethylenically unsaturated monomer, and di-t-butyl peroxide 0 as a thermal radical initiator The monomer mixture A-1 consisting of 1 part was continuously fed from the raw material tank to the reactor at a constant feed rate (23 g / min, residence time: 14 minutes), and the monomer mixture A-1 A reaction product corresponding to the supply amount was continuously withdrawn from the outlet. Immediately after the start of the reaction, once the reaction temperature decreased, a temperature increase due to the heat of polymerization was observed, but the reaction temperature was maintained at 270 to 271 ° C. by controlling the heater.
One hour after the start of the supply of the monomer mixture A-1 with a stable temperature was taken as the starting point for extracting the reaction liquid as a raw material for the next esterification reaction. As a result of continuing the reaction for 3 hours, 4140 g of the monomer mixture A-1 was supplied, and 4130 g of the reaction product was recovered.
The reaction solution was introduced into a thin film evaporator to separate volatile components such as unreacted monomers to obtain 3800 g of a product (copolymer B-1). From the gas chromatograph, no unreacted monomer was present in the concentrate. The number average molecular weight (hereinafter abbreviated as Mn) of copolymer B-1 using polystyrene as the molecular weight determined by GPC using tetrahydrofuran as a solvent is 4,100, and the weight average molecular weight (hereinafter abbreviated as Mw) is 8. 250 and the polydispersity was 2.0. The acid value of the product was 220.
[0029]
● Production of reactive resin water dispersion
A flask equipped with a stirrer and a condenser tube was charged with 50 g (0.196 eq) of copolymer B-1, 6.0 g of 25% aqueous ammonia and 186 g of water, heated to 70 ° C., stirred, Combined B-1 was dissolved. After completely dissolving the copolymer, 13.9 g (0.098 mol) of glycidyl methacrylate and 32 mg of hydroquinone monomethyl ether were charged and stirred at 75 ° C. for 2 hours, viscosity 10 cps / 25 ° C., solid content 25%, solid 256 g of reactive resin water dispersion C-1 having an acid value of 87 was obtained.
[0030]
○ Examples 2 to 4
In Example 1, the reaction was performed in exactly the same manner as in Example 1 except that the carboxyl group-containing (meth) acrylate, the type of ethylenically unsaturated monomer, and the charged parts by weight were changed according to Table 1, and the carboxyl group was reacted. A containing polymer was produced. Table 1 shows the molecular weight and acid value of the obtained carboxyl group-containing polymer.
Using each of the obtained polymers, a glycidyl methacrylate addition reaction was carried out in the same manner as in Example 1 except that the reaction was carried out under the conditions shown in Table 2 to produce a reactive resin aqueous dispersion.
The acid value and viscosity of the resulting reactive resin water dispersion are shown in Table 2.
[0031]
○ Comparative Example 1
In a four-necked flask equipped with a reflux condenser, thermometer, dropping funnel, glass tube for nitrogen replacement and stirrer, 300 g of monomer mixture A-1 similar to Example 1 and methyl ethyl ketone (hereinafter abbreviated as MEK) And 9 g of 2,2′-azobisisobutyronitrile were charged, and a polymerization reaction was carried out at 80 ° C. for 4 hours while blowing nitrogen to obtain a reaction product F-1.
350 g of the reaction product F-1 was introduced into a thin film evaporator to separate volatile components such as unreacted monomers and solvent to obtain 80 g of a product (copolymer D-1). From the gas chromatograph, no unreacted monomer was present in the concentrate. Tetrahydrofuran was used as a solvent, and the Mn of the copolymer D-1 determined by GPC was 10,500, Mw was 34,250, and the polydispersity was 3.3. The acid value of the product was 240.
A flask equipped with a stirrer and a condenser tube was charged with 50 g (0.214 eq) of copolymer D-1, 6.5 g of 25% aqueous ammonia, and 189 g of water, heated to 75 ° C., and dissolved by stirring. did. After complete dissolution, 15.2 g (0.107 mol) of glycidyl methacrylate and 33 mg of hydroquinone monomethyl ether were added and stirred at 70 ° C. for 2 hours. Viscosity 124 cps / 25 ° C., solid content 25%, solid content converted acid value 94 294 g of the reactive resin E-1 was obtained.
[0032]
○ Comparative Example 2
In a flask equipped with a stirrer and a condenser, 166 g of reaction product F-1 of Comparative Example 1 (consisting of 50 g of copolymer D-1 (0.214 eq) and 116 g of MEK), 15.2 g of glycidyl methacrylate (0 107 mol), 0.65 g of triethylamine, and 33 mg of hydroquinone monomethyl ether were added and stirred at 90 ° C. for 6 hours.
After adding 11 g of triethylamine to the obtained reaction liquid and stirring at 50 ° C. for 10 minutes, 225 g of water was added to make a dispersion liquid, and this was reduced in pressure to distill off the solvent in the dispersion liquid.
280 g of a reactive resin E-2 having a viscosity of 225 cps / 25 ° C., a solid content of 29%, and an acid value of 99 in terms of solid content was obtained.
[0033]
[Table 1]

[0034]
[Table 2]

[0035]
○ Evaluation
The reactive resin water dispersion obtained in each example was evaluated by the following methods. The results are shown in Table 3.
[0036]
・ Workability evaluation
○: No problem in work.
(Triangle | delta): Although viscosity is somewhat high, it can handle. .
X: It is difficult to handle due to high viscosity.
[0037]
・ Heating stability test
The reactive resin water dispersion obtained in each example was allowed to stand at 40 ° C. for 200 hours and then evaluated by visual appearance.
A: No change at all.
○: Almost no increase in viscosity.
Δ: Increased viscosity.
X: Aggregates and precipitates are generated.
[0038]
・ Curability test
A composition was prepared by blending 2 parts of Irgacure 2959 (manufactured by Ciba Geigy Co., Ltd.) with respect to 100 parts of the solid content of the resulting reactive resin water dispersion. This composition was applied to a bonderite steel sheet PB-144 (manufactured by Nippon Test Panel Co., Ltd.) with a film thickness of 20 microns, and then dried in an oven at 80 ° C. for 5 minutes, and then this was 80 W / cm, a condensing type Using one high-pressure mercury lamp, ultraviolet rays were irradiated at a lamp height of 10 cm, and the irradiation amount required for curing was measured.
In the table, ◎, ○, Δ and × have the following meanings.
A: Completely cured at less than 500 mJ / cm2
○: Cured at 500 or more and less than 1000 mJ / cm 2
Δ: Cured at 1000 mJ / cm2 or more
×: Not cured even at 1000 mJ / cm2 or more
[0039]
·hardness
About the cured film obtained by the sclerosis | hardenability test, it evaluated in accordance with JIS "hand-drawing method K5400".
[0040]
・ Coloring evaluation
The color of the cured film obtained by the curability test was visually evaluated.
In addition, (circle), (triangle | delta), and x in a table | surface show the following meanings.
○: No coloring at all
Δ: Slightly colored
X: Coloring is observed
[0041]
[Table 3]

[0042]
【The invention's effect】
The production method of the present invention is an industrially advantageous addition reaction of an epoxy group-containing (meth) acrylate with respect to a carboxyl group-containing polymer, and the resulting reactive resin aqueous dispersion has a low viscosity. It has excellent properties, is not colored, has excellent storage stability, or a composition comprising the resin is excellent in curability, heat stability, and transparency, so that it can be used for paints, printing inks, adhesives, and fillers. It can be used in various applications such as molding materials and resists, and its industrial value is extremely large.

Claims (2)

One or more of (meth) acrylates having one or more carboxyl groups or one or more of the (meth) acrylates and one other monomer having one ethylenically unsaturated group at 150 to 310 ° C. A polymer having a (meth) acryloyl group and a carboxyl group having an acid value of 50 to 500 and a number average molecular weight of 1,000 to 15,000, obtained by polymerization at a polymerization temperature, is added to an alkaline aqueous medium. A method for producing a reactive resin aqueous dispersion, wherein the polymer is dissolved or dispersed, and the polymer is subjected to an addition reaction with (meth) acrylate having one epoxy group. The method for producing a reactive resin water dispersion according to claim 1, wherein the polymer having a (meth) acryloyl group and a carboxyl group has an acid value of 100 to 300 and a number average molecular weight of 2,000 to 10,000.